1. Field of the Invention
The present invention relates to a printing system including a print server to be shared by a plurality of workstations, personal computers or the like.
2. Description of the Related Art
Recently, in a field of a workstation, a personal computer or the like, a LAN (Local Area Network) or a WAN (Wide Area Network) has been widely used. With the spread of the LAN or WAN, a print server to be shared by a plurality of terminals such as workstations, personal computers, word processors is advantageously employed for saving an introduction cost and installation space.
Referring to FIG. 1, there is shown a conventional printing system comprising a network 10 such as a LAN or WAN, first, second and Nth terminals 11, 12 and 13 connected to the network 10 and a print server 14 connected to the network 10, the print server 14 including a server 15, a printer controller 16 and a printer engine 17. In this printing system, printing is carried out in the following. (1) Each of the terminals 11 to 13 transmits document data 18 for representing a printing content of a document to the server 15 of the print server 14 through a path 19a of the network 10. The document data 18 comprises a string of printing commands for describing the printing content such as characters, graphics, images and so forth for each page of the document. (2) The print server 14 processes the document data as follows:
(a) Firstly, the server 15 once stores the document data 18 in a printing spool file part 152 within a file 151 of the server 15.
(b) Secondly, the server 15 reads the document data out of the printing spool file portion 152 and transmits the document data to the printer controller 16 to instruct printing of the document.
(c) The printer controller 16 processes the received document data and gives an instruction for printing the document to the printer engine 17.
(d) Finally, the printer engine 17 carries out an electrophotographic printing process or a wire dot printing process according to the instruction output from the printer controller 16 to print the document on the sheets of paper.
The conventional printing systems are disclosed in, for example, Japanese Patent Laid-Open Publication (KOKAI) Nos. 62-274331, 63-75828, 63-99644 and 63-250730.
In the conventional printing systems, since no consideration is taken (i) for sharing the print server among different kinds of terminals and (ii) for sharing the print server in case of different kinds of printing protocols used for describing the document data even when the kind of the terminals is the same, a print server is difficult to be used in common.
Conventionally, in order to overcome such problems, it is necessary to provide different print servers for dealing with the different kinds of terminals or different kinds of printing protocols, which requires much cost and gives only small performance with reference to the invested cost.
Further, in a conventional server system disclosed in Japanese Patent Laid-Open Publication (KOKAI) No. 63-75828, printing data sent from terminals are converted into another type of data adapting to the printer type of the server system. In this case, a plurality of terminals have the same data printing format, and thus this server system can not cope with the different kinds of printers nor different kinds of printing protocols.